RESUMEN
BACKGROUND AND OBJECTIVES: Epidermal growth factor (EGF), directly stimulates epidermal growth and differentiation. The combination of EGFR activation and genetic alternations may lead to neoplasia and metaplasia. To study the change of chromosomal number and the aberrations of chromosomal structure of KUMA3 cell line treated with high dose EGF. MATERIALS AND METHODS: The high dose EGF treated cell clones were obtained from KUMA3 cell line which was established from squamous cell carcinoma of the lower lip by culturing cells in medium containing high dose EGF for 6 months. The chromosomal analysis and subculture were performed at subsequent passage of 1 month interval. RESULTS: In high dose EGF treated cell clones, there was no apparent change in chromosomal number, but the ratio of the number of chromosome 7 to mode chromosome number was similar to normal value (0.043). The new chromosomal structural aberrations appeared first from 30 passage of IR-200 cell clone. The chromosomal aberrations were del(1)(q23-->qter) and del(4)t(1:4)(1qter-->1q23: : 4p16-->4qter). CONCLUSION: There was no change in chromosomal number, but the ratio of the number of chromosome 7 to mode chromosome number was similar to normal value (0.043), and the new chromosomal structural aberrations were appeared.